Fluid pressure brake



LAP

A5 RELL'A-SE Nov. 16, 1937; f E. HEWITT 2,099,395

FLUID PRESSURE BRAKE Filed Aug. 24, 1935 2 SheetsSheet 1 lNVZNTOR ELLIS E, HEWITT.

ATTORNEY Fig.1

Nov. 16, 1937.. v E. E. HEWITT 2,099,396

- FLUID PRESSURE BRAKE Filed Aug. 24, 1955 2 Sheets-Sheet 2 is QI F 18 INVENTOR ELLIS E, HEWITT ATTORNEY Patented Nov. 16, 1937 UNITED STATES waste 4 FLUID PRESSURE BRAKE Ellis E. Hewitt, Edgewood, Pa., assignor to h Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application August I 24,

. 17 Claims.

This invention relates to electropneumatic brakes and more particularly to a braking system in which the brakes may be controlled both electrically and pneumatically.

Braking systems have heretofore been developed which employ a brake pipe to supply fluid under pressure to reservoirs from which fluid is supplied to the vehicle brake cylinders to effect an application of the-brakes. In these systems the supply of fluid under pressure to the brake cylinders from the reservoirs and the release of fluid under pressure from the brake cylinders, is controlled by means of relay valve devices car- 'ried by each of the cars of a train and controlled by variations in the pressure of the fluid in a control pipe. 7

In these systems the pressure of the fluid in the control pipe is controlled by means of an en-- gineers brake valve, which controls the supply and release of fluid under pressure to and from the control pipe, either directly or through a relay valve, together with electrically operated means which controls the supply of fluid to the control pipe from the reservoirs on the cars, the supply and release of fluid Under pressure'to and from the control pipe being effected through magnet valves mounted on the cars.

I There is a possibility in the event of improper operation of the magnet valves, or a rupture of 30 the control pipe, that all of'the air will be released from the reservoirs, with the result'that no fluid under pressure will be available to effect an application of the brakes V 7 'It is a principal object of the present invention to provide a braking system of the type described, and in which the electrically operated means supplies fluid under pressure to the relay valve device and to the control pipe from a source other than the reservoirs from which fluid is'supplied to the brake cylinders, whereby the possibility of a complete loss of fluid to effect an application of the brakes as a result of improper operation of the magnet valves or a rupture of the control pipe,

1935, Serial No. 37,700

a modified form of braking system embodying my invention.

Referring to Fig. 1 of the drawings the system therein illustrated includes an engineers brake valve I, a conductors brake valve 2, a fluid pres- 51.1

sure operated valve device 3, a main reservoir a relay valve device 5, a fluid pressure operated switch device 1, a relay valve device 9, an application magnet valve device H, a release magnet valve device I2, a brake cylinder I4, a supply reservoir l5, a control pipe H, a brake pipe W, a control reservoir l9, and a change-over valve device 26.

The engineers brake valve l comprises a body having a rotary valve seat 3H, having therein a port 34 communicating with the brake pipe IS, an atmospheric exhaust port 33, and a port 35 which communicates with a pipe 36 which leads to the fluid pressure operated valve device 3.

The engineers brake valve I has a rotary valve 20 31 mounted in a chamber therein, the rotary valve having ports formed therein adapted in difierent positions of the rotary valve, as will hereinafter more fully appear, to establish communication between the chamber 39, above the rotary valve and which is constantly connected to the main reservoir t by way of the passage and pipe 10, and the brake pipe I8, and the pipe 36, or between the brake pipe, the pipe Stand the atmospheric exhaust port 33. The rotary valve 3'! is adapted to be operated between its different positions by means of a manual operating handle 42.

The conductors brake valve 2 comprises a casing indicated generally by the reference numeral 45, and having a chamber 46 therein which is constantly connected to the brake pipe i 8 by way of a pipe 48. A valve element 50 is mounted in the" chamber 46 and is normally urged into engagement with a seat rib 5'! by means of a spring 52so as to out off communication between the chamber i6 and the atmosphere by way of a passage 53. The valve element 5% has a stem 55 associated therewith which is adapted to be engaged by a lever 5'1, which is operated by means of a lever 58 having a cam portion 53 engageable with the lever 51.

When the lever 58 is rotated the cam surface 59 engages the lever 51 so as to move the lever 51 downwardly andit presses on the stem 55, so as to move the valve 50 away from the seat 5|, and thereby establish communication between the chamber 46 and the atmosphere by way of the passage '53.

' The fluid pressure operated valve device 3 comthe relay valve device 5.

prises a casing having a bore therein in which is mounted a piston having a chamber 65 at one side thereof connected to the brake pipe 59 by way of a pipe 59. The piston 55 has a valve chamber 15 on the opposite side thereof which is constantly connected to the main reservoir 4 by way of a pipe 12. A slide valve 19 is positioned in the valve chamber "59 and is slidable upon a seat 15 and has a cavity 11 therein which controls communication between a port 19, to which is connected the pipe 35 leading from the engineers brake valve and a port 89 which is connected by way of a pipe 92 with a passage in The body of the fluid pressure operated valve device 3 also has a passage 89 formed therein which has a restricted portion 85 interposed therein, the passage 55 communicating with a port in the valve seat which is adapted to be uncovered by the end of the slide valve 14 in one position of the slide valve.

The slide valve 15 is operated by means of a stem 81 associated with the piston 65, while the piston 55 is normally urged to the right, as viewed in the drawings, by means of a spring 59.

The relay valve device 5 comprises a body indicated generally by the reference numeral 99 and having a bore therein in which is located a piston 92 having on one side thereof a chamber 93 which is connected through a restricted passage 95 with a passage 95 to which is connected the pipe 82.

The piston 92 has on the other side thereof a valve chamber 98 in which is mounted a slide valve I99 which is slidable upon a seat I9I formed in the body 99, and this seat has a pair of ports I92 and I93 formed therein and communicating with the atmosphere. The slide valve IE9 is adapted to be operated by a stem I06, which is formed integral with the piston 92, while the slide valve 159 has a port I 51 extending therethrough and adapted in one position of the slide valve 599 to be substantially in alignment with the port I92 in the slide valve seat IiiI.

The body 99, in addition, has a valve chamber H9 formed therein in which is mounted a valve Ill, which is normally urged into engagement with a seat rib H2 by means of a spring H5. The valve 1 i i has associated therewith a member lit which is adapted to be engaged by the end of the stem I95.

The valve Hi also has associated therewith a pilot valve device comprising a valve element 529, which is normally urged by means of a spring I25 into engagement with a seat rib I22 formed on the member 115. The valve element I29 has a stem l25 associated therewith which is positioned in a bore in the member H5, and which projects from the face of the member H5 so as to be engaged by the end of the stem E95 before the member I i5 is engaged thereby.

The valve chamber H9 is constantly connected with the main reservoir 9 by way of a pipe and passage E39, while the valve chamber 98 is constantly connected with the control pipe 51 by way of a passage 32.

The relay valve device 5 has a pair of check valve devices associated therewith and indicated generally by the reference numerals I36 and I31. The check valve device I39 is adapted to permit flow from the passage 95' in the body 99 to the passage I32, and to cut off flow between the passage I32 and the passage 95, while the check valve device I91 is adapted to permit flow between the passage I32 and the passage 95, and to out off flow between the passage 95 and the passage I32.

The check valve device I35 comprises a chamher 549 in whichis mounted a valve element I42, and which is urged by a spring I41 into engagement with a seat rib I44 surrounding a passage I45 which communicates with the passage 95. On a predetermined increase in the pressure of the fluid in the passage 95 over that in the passage I32, the valve 32 will be lifted off from the seat rib I44 by the pressure of the fluid in the passage I45 acting on the face of the valve M2. within the seat rib M4, and fluid will thereupon flow from the passage 95 to the chamber I49 and therefrom by way of a passage M8 to the passage The check valve device I31 is similar in construction to the check valve device 136, and comprises a chamber I59 in which is mounted a valve element I5I which is normally urged by a spring I55 into engagement with a seat rib I52 surrounding a passage I53 leading from the passage I32. The chamber I59 is connected to the passage 95 by way of a passage I55, and on an increase in the pressure of the fluid in the passage I32, the fluid in the passage I53 acting on the face of the valve I5! within the seat rib I52 will cause the valve element E5I to be moved away from the seat rib I52 so as to permit fluid to flow from the passage I32 to the chamber I59 and therefrom by way of the passage I56 to the passage 95.

The relay valve device 5 has associated therewith the fluid pressure operated switch device- 1, which, as shown, comprises a pair of housing sections I and IEI, which have clamped therebetween the diaphragm I 63, which has on one side thereof a chamber I95, which is constantly connected to the passage by way of a passage I61, and which has on the other side thereof a chamber I68 which is constantly connected to the control pipe 11 by way of a passage I69.

' The diaphragm N55 has operatively connected thereto a stem I19 which is connected by means of wires I12 to one side of a source of current,

such as a battery E13, the other side of which is connected to ground.

The housing section I5I of the fluid pressure operated switch device 1 has mounted thereon adjacent the end of the stem I10 a contact I15 which is connected by way of a wire I11 with the winding of the release magnet valve device I2. In addition, the housing section 169 of the fluid pressure operated switch device 1 has mounted thereon a contact I18 which is connected by way of a wire 119 with the winding of the application magnet valve device I I. The stem i'iil is adapted in one position of the diaphragm I59 to engage the contact i15 to complete a circuit through this contact from the battery I13, and in another position of the diaphragm I63 to engage the contact I19 and establish a circuit through this contact from the battery I13.

The diaphragm 593 is constructed so as to normally maintain the stem H19 in engagement with the contact I15 and thus maintain a circuit through the winding of the release magnet valve device I2.

The relay valve device 9 comprises a body I35 having a bore therein in which is mounted a piston 185 having a chamber 58 on one side thereof which is connected with the control pipe I1 by way of a passage I89, having a check valve I90 interposed therein.

of a slide valve chamber I9 I, in which is mounted a slide valve I92 which is adapted to be operated by means of a stem I94 associated with the piston I86, and which controls communication between the chamber I9! and the atmosphere by way of a passage I95.

The body I85, in addition, has a valve chamber I9! formed therein in which is mounted a valve element I99 which is normally urged into engagement with a seat rib 29! by means of a spring 292 so as to cut oil communication between the valve chamber I9! and. the slide valve chamber I9I.

The valve element I99 has a member 204 associated therewith and adapted to be engaged by the end of the stem I94.

. The valve I99, in addition, has associated therewith a pilot valve comprising a valve element 296 which is normally urged into engagement with a seat rib 268 on the member 264 by means of a spring 289, and which has associated therewith a stem 2I2 positioned in a bore extending through the member 204, the stem 2I2 projecting from the face of the member 264 so as to be engaged by the end of the piston stem I94 before the member 264 is engaged thereby.

' The valve chamber I9! is constantly connected with the supply reservoir I5 by way of a passage and pipe 2l5, while the slide valve chamber I9! is constantly connected with the brake cylinder I4 by way of a pipe and passage H6.

The relay valve device 9 has associated therewith a check valve device indicated generally by the reference character 220, and comprising a chamber 22!, which is constantly connected with the supply reservoir I5 by way of a passage 223 and the passage 2 I5, and this chamber has positioned therein a valve element 225 which is normallyurged into engagement with a seat rib 22'! by means of a spring 229, while the area within the seat rib 22'! is constantly connected to the brake pipe I! by way of a passage 238.

The control reservoir I9 is connected to the passage 239, and thereby to the brake pipe I8, by way of a pipe 235 having a check valve 236 interposed therein, and adapted to permit fluid to flow from the passage 236 to the control reservoir I9, and to cut ofi the flow of fluid from the control reservoir I9 to the passage 238. The pipe 235 also has a restricted portion or choke 239 interposed therein and adapted to restrict the rate of flow of fluid from the brake pipe I8 to the control reservoir I9.

The application magnet valve II comprises a casing having a chamber 25!] therein in which is mounted a valve element 252 which is normally urged into engagement with a seat rib 253 by means of a spring 255, and by the pressure of the fluid in a chamber 25! on the upper side of the valve element 252.

The valve element 252 is urged away from the seat rib 253 by the pressure of the fluid in the chamber 259 acting on the'face of the valve element 252 outwardly of the seat rib 253. The valve element 252 controls communication between the chamber 256, whichis constantly con nected to the control reservoir I9 by way of a pipe and passage 258, and a chamber 266 which is constantly connected to the control pipe I! and the chamber !88 of the relay valve device 9 by Way of a passage 26! which has a choke or restricted portion 263 interposed therein.

The application magnet valve device also includes a casing section having a chamber 265 formed therein in which is mounted a double beat valve element 266 which controls communication between the chamber 265 and a chamber 268 and a chamber 269. The chamber 268 is constantly connected to the atmosphere, while the chamber 269 is constantly connected to the chamber 258 by way of a passage 21!. The chamber 265 is constantly connected to the chamber 25'! on the upper sideof the valve element 252 by means of a passage 213.

The valve element 266 is normally held in engagement with its upper seat by means of: a spring 215 so as to cut off communication between the chamber 265 and chamber 268, and is urged downwardly against this spring to its lower seated position by the winding of the magnet valve device on energization thereof so as to cut off communication between the chamber 265 and the chamber 269.

The release magnet valve device I2 comprises a casing having a chamber 289 therein which communicates by way of a passage 28! with the passage 26! which communicates with the control pipe I'!, and the chamber 289 has mounted therein a valve element 282 which is normally held in engagement with a seat rib 289 by meansof a spring 285 and by the pressure of the fluid in a chamber 28'! on the upper side of the valve element 282.

The valve element 282 controls communication between the chamber 289 and thereby the control pipe !'I, and a chamber 298 which is constantly connected to the atmosphere by way of a passage 292 having a restricted portion 293 interposed therein.

The release magnet valve device I2 also includes a casing section having a chamber 295 formed therein in which is mounted a double beat valve element 296. The chamber 295 is in constant communication with the chamber 281 on the upper side of the valve element 282 by means of a passage 296, while the valve 296 is adapted to control communication between the chamber 295 and a chamber 299, which is constantly connected with the chamber 296 by way of a passage 36!, and a chamber 393 which is constantly connected to the atmosphere.

The double beat valve element 296 is urged to its upper seated position by means of a spring 365 so as to cut off communication between the chamber 295 and the chamber 363, and is moved to its lower seated position, as shown in the drawings, on energization of the winding of the magnet valve device so as to cut off communication between the chamber 295 and the chamber 299.

The change-over valve device 29 comprises a casing having a valve chamber 329, which is connected to the brake pipe I8 by way of a passage 32!, which has a choke 322 interposed therein, and by way of the passage 239. The passage 32! alsocommunicates with a pressure chamber 325 by way of a passage 326.

The valve chamber 329 contains a slide valve 32'! which is controlled by a stem 328 which has secured thereto the diaphragms 338 and 33!, which diaphragms are of unequal diameter, the diaphragm 336 being substantially larger in diameter than the diaphragm 33!.

The diaphragm399 is subject on one side to the pressure of the fluid in the valve chamber 329, and is subject on the other side to the pressure of the springs 339 and 335.

A stop 33'! is provided which engages the end of the stem 328 to limit upward movement of the stem 328, while the end of the stem 328 engages the wall of the chamber 338 to limit downward movement thereof.

The diaphragm 33I is subject on one side to the pressure of the fluid in the valve chamber 328, and is subject on the other side to the pressure of the fluid in chamber 333, which communicates by way of the passage 339 with the chamber I88 in the relay valve device 9.

The stem 328, therefore, is moved upwardly by the pressure of the fluid in the valve chamber 328 acting on the lower face of the diaphragm 339, and by the pressure of the fluid in the chamber 338 acting on the lower face of the diaphragm 33I, and is urged downwardly by the pressure of the fluid in the valve chamber 329 acting upon the upper side of the diaphragm 33I and by the springs 334 and 335.

The slide valve 321 has a port 349 formed therein and controls communication between the passage 34I, which communicates with the control passage I89 on the side of the check valve I98 remote from the relay valve device, and the passage 342 which communicates by way of the passage 339 with the chamber I98 in the relay valve device 9.

The slide valve 321 also controls communication between the passage 345, which communicates with the sup-ply reservoir I5 by way of the passage 223, and the passage 342 which communicates with the chamber I88 in the relay valve device.

The port 340 in the slide valve 321 is arranged so that when the stem 328 is in the upper position communication is established between the passages 34I and 342, and communication is cut off between the passages 345 and 342, while in the lower position of the stem 328 communication is cut off between passages MI and 342 and JiS established between the passages 342 and 345. The port 348 is also arranged so that in an intermediate position of the stem 328 communication is cut oil between the passage 342 and both of the passages 34I and 345. This is the lap position of the change-over valve device.

The details of construction of the change-over valve device 29 form no part of the present invention, and this valve device is described and claimed in my application Serial No. 31,224 for a patent on brake control valves, filed July 13, 1935.

In the installation of a system of this type on a train, the engineers brake valve I, the conductors brake valve 2, the fluid pressure operated valve device 3, the main reservoir 4, the relay valve device 5, and the fluid pressure operated switch device 1 are mounted on the engine, and each of the cars of the train is provided with a relay valve device 9, an application magnet valve device II, a release magnet valve device I2, a brake cylinder I4, a supply reservoir I5, a control reservoir I9, and a change-over valve device 29, while the control pipe I1 and the brake pipe I8 extend throughout the entire length of the train, the connections between the cars being made by means of flexible couplings. 'A conductors brake valve 2 may also be installed on each of the cars of the train. In addition, the wires I11 and I19 extend throughout the length of the train.

In the operation of the system, assuming that the main reservoir 4 is charged with fluid under pressure and that the operating handle 42 of the engineers brake valve device I is turned to the release position, fluid will flow from the main reservoir by way of the pipe and passage 48 to the chamber 39 in the engineers brake valve device, and therefrom by way of a passage in the rotary valve 31 to the port 3I and the brake pipe I8. If desired the pressure of the fluid supplied from the main reservoir may be reduced by means of a feed valve (not shown). Fluid which is supplied to the brake pipe I8 flows therethrough to the relay valve device 9, and the fluid which is supplied to the passage 238 in the relay valve device flows by way of the pipe 235 and the choke 238 and through the check valve 236 to the control reservoir I9 charging said reservoir. Fluid supplied to the control reservoir I9 flows therefrom by way of the pipe 258 to the chamber 250 of the application magnet valve device II and from this chamber fluid flows by way of the passage 2' to the chamber 269. Fluid supplied to the chamber 269 flows past the double beat valve 266 to the chamber 265 and therefrom by way of the passage 213 to the chamber 251 on the spring side of the valve 252 where it acts upon the valve 252 to maintain it seated on the seat rib 253. In addition, fluid which is supplied to the passage 238 unseats the valve element 225 so that fluid flows to the chamber 22I in the check valve 228 and therefrom by way of the passage 223 to the supply reservoir I5 charging this reservoir with fluid under pressure.

Fluid which is supplied to the brake pipe I8 also flows by way of the pipe 69 to the chamber 66 in the fluid pressure operated valve device 3, while fluid under pressure from the main reservoir 4 flows by way of the pipe I2 to the valve chamber ID on the opposite side of the piston 65 of the valve device 3, and as the pressures on the opposite sides of said piston 65 are substantially equal, the piston will be moved to the position in which it is shown in the drawings by means of the spring 88, in which position the slide valve I4 cuts off communication through the port 84, while the cavity 11 establishes communication between the ports 19 and 88.

Fluid which is supplied to the brake pipe I8 also flows by way of the choke 322 and the passages 32 I and 326 to the pressure chamber 325, and by way of the passage 32I to the valve chamber 328 in the change-over valve device 29, where the fluid under pressure acting on the differential areas of the diaphragms 339 and 33I moves the stem 326 and the slide valve 321 to the position in which they are shown in the drawings, in which position the port 348 in the slide valve establishes communication between the passages MI and 342, with the result that control pipe I1 is connected to the chamber I88 of the relay valve device 9 by way of the passage 339 which by-passes the check valve I98. This permits fluid to be released from the chamber I88 through the control pipe I 1.

Fluid also flows from the main reservoir 4 by way of the pipe I39 to the chamber III! in the relay valve device 5, while fluid from the brake pipe I3 flows by way of the pipe 48 to the chamber 43 in the conductors brake valve 2.

When it is desired to effect an application of the brakes the operating handle 42 of the engineers brake valve I is turned to the service position, in which position communication is maintained between the chamber 39, which is connected to the main reservoir, and the brake pipe I8, as is clearly shown in Fig. 2 of the drawings, which is a diagrammatic view of the ports in the engineers brake valve. When the operating handle 42 is turned to the service position a communication is established between the chamber 39 and the port 35 which has the pipe 36 connected thereto, the communicationbeing by way of a choke or restricted portion 38 to limit the rate of flow of fluid from. the main reservoir to the pipe 36.

Fluid which is supplied to the pipe 38 flows therethrough to the port 19 in the fluid pressure operated valve device 3, and therefrom by way of the cavity 11 in the slide valve 14 to the port 88 and thence by way of the pipe 82 to the passage 95 in the relay valve device 5.

Fluid which is supplied to the passage 95 flows therefrom to the passage I91 in the fluid pressure operated switch device 1 and thence to the chamber I95, where it forces the diaphragm I63 downwardly and moves the stem I19 out of engagement with the contact I15, thereby interrupting the circuit through the winding of the release magnet valve I2, and into engagement with the contact I18. When the stem I10 en a es the contact I18 a circuit is established which includes the battery I13, the wire I12, the contact I18, and the wire I19 which is connected to one side of the winding of the application magnet valve device II, the other side of which is connected to ground.

Upon energization of the winding of the application magnet valve device II the double beat valve element 268 is forced downwardly against the spring 215 so as to cut off communication between the chamber 299 and the chamber 295, and to establish communication between the chamber 265 and the atmosphere by way of the chamber 288. This permits fluid to escape from the chamber 261, on the upper side of the valve r element 252, to the atmosphere, and on the release of this fluid under pressure, the fluid in the chamber 259 acting on the portion of the valve element 252 outwardly of the seat rib 253 forces this valve element upwardly so as to permit fluid to flow from the chamber 259 to the chamber 260, and therefrom through the restricted passage 253 and the passage 26I to the control pipe I1 and the passage I89 in the relay valve device 9 which leads to the chamber I88 of the relay valve device.

Fluid supplied to the passage I89 and to the control pipe I1 by the application magnet valve device II, or by any other means, also flows by way of the passage 28I to the chamber 288 in the release magnet valve device I2, and therefrom by way of the passage 3III to the chamber 299. Fluid supplied to the chamber 299 flows past the double beat valve 298 which is in its upper seated position at this time, to the chamber 285 and therefrom by way of the passage 298 to the chamber 281 on the spring side of the valve 282, where it acts upon the valve 282 and serves to maintain the valve in engagement with the seat rib 284.

The fluid which is supplied to the passage 95 in the relay valve device 5 also flows by way of,

this passage and the restricted portion 99 to the chamber 93 on the left hand side of the piston 92, and forcesthis piston to the right as viewed in Fig. 1 of the drawings, and after a certain amount of movement of the piston 92, the stem I96 engages the end of the slide valve I98 and moves it to the right so as to cut off communication through the ports I92 and I83.

On further movement of the piston 92 the end of the stem I96 engages the end of the stem I25 of the pilot valve element I20 so as to move this valve element away from the seat rib I22 against the spring I24. This permits fluid to flow from the chamber III] to the valve chamber 98 at a slow rate so as to permit the pressures in these chambers to approach equalization and thus re,-

duce the force exerted by the fluid in the chamber III] acting on the valve element III and tending to 'hold the valve element against the seat rib I I2.

On furthermovement of the piston 92 the stem I98 will engage the member H6 and the valve I I I will be forced away from the seat II2 against 7 The fluid which is supplied to the passage 95 also flows by way of the passage N55 to the chamber on the lower side of the valve element I42 of the check valve device I36 and, on a predetermined increase in the pressure of the fluid in the pipe 95, the valve element I42 will be moved away from the seat rib i i i against the spring I91, and fluid will thereupon flow from the passage 95 to the chamber I 99 which is connected by way of the passage I48 to the passage I32 which leads to the control pipe I1.

.It will be seen, therefore, that on movement of the handle 92 of the engineers brake valve I to the service position fluid may be supplied to the control pipe from a plurality of sources, one of these being by way of the application magnet valve device II, another being by operation of the relay valve device 5, and another being by the supply of fluid to the passage I32 directly from the engineers brake valve by way of the pipe 82 and passage 95.

On an increase in the pressure of the fluid in the control pipe I1 the pressure of the fluid in the chamber I88 in the relay valve device 9 will be increased, and the piston I38 will be forced downwardly so that the end of the piston stem I94 engages the stem 2I2 of the pilot valve 288 causing the pilot valve 288 to be forced away from the seat rib 288 against the spring 299. In addition the slide valve I92 will be moved toa position to cut off communication through the passage I95.

Thereupon fluid will flow at a slow rate from the valve chamber I91, which is constantly connected to the supply reservoir I5 by way of the passage and pipe 2I5, to the slide valve chamber I9I, which is connected to the brake cylinder'I l by way of the pipe and passage 2I8.

When the pilot valve 295 is unseated the pressures in the valve chamber I91 and in the slide valve chamber I9I will tend to equalize, thus reducing the force exerted by the fluid'under pressure in the chamber I91 and tending to hold the valve I99 against the seat rib 29L Thereafter, on further movement of the piston I85 downwardly, the valve I99 will be moved away from the seat rib 2M against the spring 282, and fluid will flow from the valvechamber I91 to the slide valve chamber I9I and therefrom to the brake cylinder H5 at a more rapid rate.

On an increase in the pressure of the fluid in the control pipe I1 there will be a similar increase inthe pressure of the fluid in the chamber I89 of the fluid pressure operated switch device 1 which is connected to the control pipe I1 by way of a passage I69, and when this pressure increases to a value substantially equal to that in by nfians of the application magnet valve device Similarly, assuming that the handle 42 of the engineers brake valve has been moved from the service position to the lap position, which results in the cutting off of the flow of fluid from the main reservoir to the pipe 36 and therefrom to the passage 95, the supply of fluid to the chamber 93 will be cut oil, and, as soon as the pressure in the valve chamber 98 increases toa value substantially equal to that in the chamber 93, the piston 92 will be moved to the left and the stem I86 will move the slide valve II!!! to the lap position, While the stem I96 will move out of engagement with the member H6 and the stem I25 of the pilot valve I29 so as to permit the valve III and the pilot valve I20 to seat and cut off the supply of fluid to the valve chamber 98 and to the passage :32 from the main reservoir.

Likewise, when the supply of fluid under pressure to the pipe 36 is cut ofi, the supply of fluid to the passage 95 will be out 01f, and fluid can no longer flow from the passage 95 past the check valve I36 to the passage I32.

It will be seen, therefore, that when the handle 42 of the engineers brake valve 1 is turned to the lap position, after having been moved to service position, the relay valve device 5 will operate to cut off the supply of fluid under pressure to the control pipe I! by the valve device as soon as the pressure in the control pipe I! increases to a value substantially equal to that established by operation of the engineers brake valve I in the pipe 82 leading to the relay valve device. Similarly the fluid pressure operated switch device I will operate to cut off the supply of fluid to the control pipe I! by operation of the application magnet valve device II as soon as the pressure of the fluid in the control pipe IT increases to a value substantially equal to that supplied to the fluid pressure operated switch device I by operation of the engineers brake valve I.

The relay valve device 9 will operate to supply fluid under pressure to the brake cylinder I4 until the pressure established therein and in the valve chamber I9I is substantially equal to that in the chamber I88 on the opposite side of the relay valve device piston I86, whereupon the piston I86 will be moved upwardly to the lap position, in which position the stem I94 is moved out of engagement with the member 284, and the stem 2 I2 associated with the pilot valve 296, while the slide valve I92 laps the exhaust port I95.

If it is desired to increase the degree of application of the brakes the handle 42 of the engineers brake valve is turned to the service position so as to again supply fluid under pressure to the pipe 36 and therefrom to the pipe 82 which leads to the passage 95 in the relay valve device 5, thereby increasing the pressure of the fluid in the chamber I65 of the fluid pressure operated switch device I, thus causing the diaphragm I63 to move downwardly so as to move the stem I18 into engagement with the contact I18, and thus establish a circuit through the winding of the application magnet Valve device II so as to cause this magnet valve device to again supply fluid from the reservoir I9 to the control pipe 11. In addition, the pressure of the fluid in the chamber 93 of the relay valve device 5 will be increased and this valve will be caused to operate to supply fluid to the control pipe Il. This increase in the pressure of the fluid in the control pipe I! results in an increase in the pressure of the fluid in the chamber I88 of the relay valve device 9, and causes this valve device to again operate to supply fluid under pressure to the brake cylinder I4.

When the desired degree of brake application has been secured the operating handle 42 of the engineers brake valve is returned to the lap position so as to cut off the supply of fluid under pressure to the chamber 93 of the relay valve device 5, and to the chamber I65 of the fluid pressure operated switch device I, and when the pressure of the fluid in the control pipe I! increases to a sufficient value, the relay valve device 5 and the fluid pressure operated switch device I will again move to the lap position.

If it is desired to efiect an emergency application of the brakes the handle 42 of the engineers brake valve is turned to the emergency position, in which position the ports in the rotary valve 3! establish communication between the chamber 39 and the port 35, which has the pipe 36 connected thereto, this communication not having a choke therein as does the port through which communication between these points is established in the service position of the engineers brake valve.

In addition, when the handle 42 is turned to the emergency position the rotary valve 37 cuts off communication between the chamber 39 and the port 3! leading to the brake pipe I8, and the ports in the rotary valve 31 establish communication between the port 3I and the atmospheric exhaust port 33 so as to release fluid from the brake pipe I8.

On a reduction in the pressure of the fluid in the brake pipe I8 there will be a similar reduction in the pressure of the fluid in the chamber 66 of the fluid pressure operated valve device 3, and the piston 65, being subject on the opposite side to main reservoir pressure in the Valve chamber ID will be moved to the left as viewed in Fig. 1 of the drawings, against the spring 88, and the stem 8! will move the slide valve I4 on the valve seat I5 so that the cavity 11 in the slide valve no longer establishes communication between the ports I9 and 80, and so that the end of the slide valve I4 uncovers the port 94, with the result that fluid under pressure will flow from the main reservoir by way of the pipe I2 to the valve chamber i3 and therefrom through the restricted passage 86 and the port 84 to the pipe 82 leading to the relay valve device 5.

During the time interval after the handle 42 has been moved to the emergency position and before the piston 65 is moved to the left as viewed in Fig. 1 of the drawings, fluid under pressure will flow through the brake valve device I to the pipe 36 and therefrom to the port 59 and the cavity TI to the passage 80 and therethrough to the pipe 82, but on movement of the piston 85 as a result of the reduction in pressure of the fluid in the brake pipe, the supply of fluid to the pipe 82 from the pipe 36 will be cut off, and fluid will thereafter be supplied to the pipe 82 from the valve chamber Ill.

The rate of flow of fluid to the pipe 82 and therefrom to the chamber 93 in the relay valve device 5 and the chamber I65 in the fluid pressure operated switch device I is somewhat more rapid through the choke 86 than through the port in the rotary valve 31 through which fluid is supplied to the pipe 82 when the engineers brake valve I is in the service position. This results in a more rapid increase in the pressure of the fluid in the relay valve device 5, and in the fluid pressure operated switch device I, than occurs during a service application of the brakes so that these devices .are very quickly conditioned' to increase the pressure of the fluid in the control pipe I! and thus effect anapplication of the brakes. s a In addition, on the reduction in the pressure of the fluid in the brake pipe I8, the pressure of the fluid in the valve chamber 320j=ofLthe change-over valve device 28 will be reduced after a time interval determined by the time required supply reservoir I5 to the chamber I88 of the relay valve device 9.

In this position of the change-over valve device fluid may also be supplied to the chamber I88 from the control pipe I! by way "of the passage I89 and past the check valve I98, but the release of fluid from the chamber 388 through the control pipe will be cut off by the. check valve I98 and by the slide valve 32! which cuts off communication between the passages 3M and 342 and thereby through the passage which bypasses the check valve I98.

An emergency application of the brakes may also be effected by means of the conductors brake valve 2, by turning the lever 58 which causes the cam surface 59 to press upon the endof :the lever 51, thereby forcingthe stem 55 downwardly and moving the valve 59 away from the seat rib 5!, thus permitting fluid to escape from the brake pipe I8 byway of the pipe 38.

The consequent reduction in the pressureof the fluid in the brake pipe t8, which will take place even though the engineers brake valve I is in the release or lap position, in which position fluid is supplied to thebrake pipe at a rate less rapid than the rate at which fluid is vented from the brake pipe I8 by means of the conductors brake valve, causes the piston of the fluid pressure operated valve device 3 to bemoved to the emergency position and supply fluid under pressure to the pipe 82 to effect an application of the brakes. I I

In addition, as a result of the reduction in the pressure of the fluid in the brake pipe which is produced by operation of the conductors valve, the change-over valve device 28 operates as de-' scribed above to supply fluid from the reservoir I5 to the chamber I88 of the relay valve device and thereby produce an application of the brakes.

Inv order to effect a release of the brakesafter an application the handle 42 of the engineers brake valve I is turned to the release position, in which position the ports in the rotary valve 37 establish communication between the chamber 39 and the brake pipe I8 so as to reestablish the pressure of the fluid in the brake pipe, if there has been a reduction in the pressure of the fluid in this pipe, and at the same time the ports in the rotary valve 31 establish communication between. the port 35 leading from the pipe 38, and the atmospheric exhaust port 33.

When; the :port 35 is connected to the atmospheric exhaust port 33 fluid under pressure is permitted: to flow from the pipe 38. to the atmosphere; and as; the pipe .38 isincommunication with .the'pipe 82 and the passage of the relay valve device 5 by way of the cavity H in the slide valve 14 of the fluid pressure operated valve device 3, fluid will flow from the passage 95 to the atmosphere. j

.If, at the time the engineers brake valve 1 is turned to the release position, the slide valve I4 is not in the position in which the cavity 11 establishes communication between the ports 19 and 88, it will be moved to this position as soon as the pressure of the fluid in the brake pipe I8 is reestablished.

"On the release of fluid under pressure. from th'epassage 95 fluid will be released from the chamber I85 in the fluid pressure operated switch device 1, and" on a reduction in the pressure of the fluid in. the chamber I85 the diaphragm I83 .will be moved upwardly by the pressure of the fluid in the chamber I88 on the lower side thereof; and the stemI'Ill will. be moved into engagement with the contact I15, thereby establishing a circuit through the wire I'II which'l'eads to the winding of the release magnet valve device I2.

On energization of the winding of the release magnet valve device I2 the double beat valve element 298 associated with this valve device'is moved downwardly to cut ofi" communication bethefl'uid in the chamber 288 acting on the portion of the valve 282 outwardly of the seat rib 284- forces the valve 282 upwardly against the spring 285 and away from the seat rib 284 to permit fluid to flow from the chamber 280 to the chamber 298, and therefrom to the atmose phere by way of the passage 292 having the choke 293 interposed therein.

' The chamber 288 is connected to the control pipe IT by way of the passage 281, so that on the release of fluid from the chamber 288 fluid will be released from the control pipe I1.

On the release of fluid under pressure from the'pass-age 95 in the relay valve device 5, fluid will also be ventedfrom the chamber 93 and the piston 92 will be moved to the left by the fluid under pressure in the valve chamber 98 so that the stem I06 moves the slide valve I08 to the position in which it is shown in Fig. 1 of the'drawings, in which position communication is established by way of the port I 8'! through the slide valve I99 with the port I92 in the slide valve seat, and between the valve chamber 98 and the port I83 so that fluid is released from the slide valve chamber 98 to the atmosphere, while the valve element III and the pilot valve I28 are permitted to move to their seats if they are not already in engagement therewith.

On the release of fluid under pressure from the valve chamber 98 fluid is vented from the passage I32 and from the control pipe I'I.

Ifthe handle 42 of the engineers brake valve I- is'left in the'release position, all of the fluid in the pipe38 and in the passage 95, will be vented to the atmosphere so that substantially no fluid under pressure will be present in the chamber I85 ofthe switch device 'I' or in the chamber 93of the relay valve device 5.

I! will continue to reduce until it is reduced a value substantially equal to that in the chamber 93 of the relay valve device 5 and the chamber I65 of the switch device I. When the pressure of the fluid in the chamber I68 is reduced to a value substantially equal to that in the chamber I65 on the opposite side of the diaphragm I63 the diaphragm is held in the position in which the stem I1!) is out of engagement with the contact [18 and in engagement with the contact I15, thereby interrupting the circuit to the winding of the application magnet valve device II and maintaining a circuit through the winding of the release magnet valve device I 2. The control pipe I'I therefore will be connected to the atmosphere by way of the valve chamber 98 and the ports I 62 and I03, and by way of the release magnet valve device I2.

On the release of fluid under pressure from the control pipe I I fluid will be released from the chamber I88 on the upper side of the piston I86 of the relay valve device 9, and this piston will thereupon be forced upwardly by the pressure of the fluid in the slide valve chamber I9I on the lower side of the piston I86, thus causing the slide valve I92 to be moved to a position to uncover the exhaust passage I95; and permit fluid to escape from the brake cylinder I4 to the atmosphere by way of the pipe and passage 2I6, the slide valve chamber I 9|, and the atmospheric passage I 95. This effects a release of the brakes.

After an emergency application of the brakes the release of fluid from the control pipe I1 is not effective to release fluid from the chamber I88 of the relay valve device 9 until the pressure of the fluid in the brake pipe is restored, which effects an increase in the pressure of the fluid in the valve chamber 329 of the change-over valve device 20, causing the slide valve 321 thereof to be moved to a position to again establish communication through the passage which by-passes the check valve I98. Fluid will thereupon flow from the chamber I88 to the control pipe IT or to the release magnet valve device I2.

It will be seen that in the braking system provided by this invention the application magnet valve device II supplies fluid under pressure to the control pipe'from a reservoir separate from the reservoir from which fluid under pressure is supplied to the brake cylinder I4. The supply reservoir I5, therefore, will not be depleted as a result of improper operation of the application magnet valve device I I or as a result of the rupture of the control pipe I'I.

It will be seen also that the control reservoir I9 from which fluid under pressure is supplied to the control pipe IT by means of the application magnet valve device I I is charged from the brake pipe I8 through -a choke or restricted portion 238, and the rate of flow of fluid from the brake pipe to the control reservoir I9 is relatively low, and hence on a reduction in the pressure of the fluid in the reservoir I9 as a result of operation of the application magnet valve device II fluid will not be taken from the brake pipe I8 rapidly enough to produce a sufficient reduction in the pressure of the fluid in the brake pipe to effect operation of the change-over valve device 20 which is responsive to the pressure of the fluid therein. This eliminates the possibility of an undesired application of the brakes as a result of a reduction in brake pipe pressure caused by the flow of fluid to the reservoir I9.

In Fig. 3 of the drawings I have illustrated a modified form of the braking system embodying my invention. The system illustrated in this figure of the drawings is generally similar to that shown in Fig. 1 of the drawings, and identical reference characters are employed for the elements of the system which are identical with those employed in the system shown in Fig. l.

The system shown in this figure of the drawings differs from that shown in Fig. 1 of the drawings in'that in place of the reservoir I9, which is charged from the brake pipe I8 in the system shown in Fig. 1 of the drawings, a separate reservoir 35I is employed which is charged from a separate supply line 358 which extends throughout the length of the train and which may be supplied with fluid under pressure from a suitable source, such as the main reservoir 4 employed in the system shown in Fig. 1.

The reservoir 35I is charged with fluid under pressure from the pipe 359 by way of a pipe 352 having interposed therein a choke or restricted portion 354, and a check valve 355, which is adapted to permit fluid to flow from the pipe 359 to the reservoir 35I and to out off the'flo-w of fluid in the opposite direction.

The application magnet valve device II is supplied with fluid under pressure from the reservoir 35! by way of a pipe 358 which corresponds to the pipe 258 in the system shown in Fig. 1 of the drawings.

The operation of the system shown in Fig. 3 of the drawings is generally similar to that shown in Fig. 1 of the drawings and will not be described in detail.

It will be seen that in each of the systems shown in this application a source of fluid under pressure separate from that from which fluid is supplied to the brake cylinder I4 is provided, and from which the application magnet valves employed in these systems supply fluid under pressure to the control pipe. It will be seen, therefore, that in each of these systems the source of fluid employed to eirect anapplication of the brakes will not be depleted as a result of improper operation of the application magnet valve devices or of rupture of the control pipe.

While a preferred embodiment and one modification of the braking system embodying my invention has been illustrated and described in detail, it should be understood that this invention is not limited to these details of construction, and that numerous changes and modifications may be made without departing from the scope of the following claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a fluid pressure braking system, in combination, a brake cylinder, a supply reservoir, a control reservoir, a brake pipe, a relay valve device operated by an increase in fluid pressure for supplying fluid under pressure from the supply reservoir to the brake cylinder, means for supplying fluid under pressure from the control reservoir to the relay valve device, means for supplying fluid under pressure to the control reservoir from the brake pipe, and means to control the rate of flow of fluid from the brake pipe to the control reservoir.

2. In a fluid pressure braking system, in combination, a brake cylinder, a supply reservoir, a control reservoir, a brake pipe, a relay valve device operated by an increase in fluid pressure for supplying fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for efiecting supply of fluid underpressure to the relay valve device, electroe responsive-means for-.- supplying fluid under pres; sureikfrom; the. control:,,reservoir to, the relay valve device, and; means riorr'supplying fluid under-phase sure to thecontroireservoirfrom the brake. pipe. r='3;.,In-1 a'fluid pressure braking system, in come binationyavbrakeicylinder, a supply reservoir, a

control.reservoinja brake, pine, a supply pipe, a relayvalveidevice operated by." an increase in fluidipressureainr supplying fluid under pressure frorn-the-supply reservoir to. the. brake cylinder, valve meansiior supplying; fluid under pressure from zthecontrol reservoir to the .relay valve vice, manually operable means. for supplying fluid under pressure to the.-re1ay-'valve; devic and means ior' supplying; fluid under pressure from the supply; pipe.- to the control reservoir...

4,. In a fluid pressure braking. system, incom= bination, a brake cylinder, a. supplyreservoir, a controlireservoir, a. brake pipe, a. supply pipe, a

relay valve device operated by an increase in fluid pressure; for supplying fluid under pressure from the supply reservoir to the brake cylinder, manually .contrclled=..valve means for supplying fluid under pressure to the relay valve device, electroresponsive means for supplying fluid under pressure from the control reservoir to the relay valve device, and means for supplying fluid under pressure from the supply pipe to the control reservoir.

5. In a fluid pressure braking system, in combination, a brake cylinder, a supply reservoir, a control reservoir, a brake pipe, a supply pipe, a relay valve device operated by an increase in fluid pressure for supplying fluid under pressure from the supply reservoir to the brake cylinder,

, valve means for supplying fluid under pressure from the control reservoir to the relay valve device, manually operable means for supplying fluid under pressure to the relay valve device, means for supplying fluid under pressure from the supply pipe to the control reservoir, and means to out off the flow of fluid from the control reservoir to the supply pipe.

6. In a fluid pressure braking system, in combination, a brake cylinder, a supply reservoir, a control reservoir, a brake pipe, a control pipe, a relay valve device operated by an increase in fluid pressure in the control pipe for supplying fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for effecting supply of fluid under pressure to the control pipe, and electroresponsive means for supplying fluid under pressure to the control pipe from the control reservoir.

'7. In a fluid pressure braking system, in combination, abrake cylinder, a supply reservoir, a control reservoir, a brake pipe, a control pipe, a relay valve device operated by an increase in fluid pressure in the control pipe for supplying fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for effecting supply of fluid under pressure to the control pipe, electroresponsive means for supplying fluid. under pressure to the control pipe from the control reservoir, and means for supplying fluid under pressure to the control reservoir from the brake pipe.

8. In a fluid pressure braking system, in combination, a brake cylinder, a supply reservoir, a control reservoir, a brake pipe, a control pipe, a relay valve device operated by an increase in fluid pressure in the control pipe for supplying fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for effecting supply of fluid under pres.- sure, to the, control pipe, electroresponsive means for. supplying fluid under pressure to, thecontrol pipe fromthe. control reservoir, means. for sunplying fluid under pressure to the control reservoirfrom thebrakepipe, and means for control-v ling therate of flowof fluid to the control reservoir from the brake pipe. 6 x

9. In a fluidpressure brake equipment, in combination, afbrake cylinder, a brake pipe,,a supply reservoir; a. control reservoir, a relay 'valve device operative on an increase in the pressure of the fluidsupplied thereto to supply fluid under pressure from the supply reservoir to the brake cylins der valve means for'supplying fluid under pressure from thecontrol reservoir to the relay valve device, a valve device subject to and operated upon a. reduction in the pressure of the fluid in the brake pipe to supply fluid under pressure to the relay valvedevice, means for supplying fluid under pressure from the brake pipe to the com trol reservoir, and means; to control the rate of flow of fluid from the brake pipe to the control reservoir. y

10. In a fluid pressure brake equipment, in combination, a brake cylinder, a brake pipe, a supply reservoir, a control reservoir, a relay valve device operative on an increase in the pressure of the fluid supplied thereto to supply fluid under pressure from the supply reservoir to the brake cylinder, valve means for supplying fluid under pressure from the control reservoir to the relay valve device, a valve device subject to and operated on a reduction in the pressure of the fluid in the brake pipe to supply fluid under pressure from the supply reservoir to the relay valve device, means for supplying fluid under pressure from the brake pipe to the control reservoir, and means to control the rate of flow of fluid from the brake pipe to the control reservoir.

11. In a fluid pressure brake equipment, in combination, a brake cylinder, a brake pipe, a supply pipe, a supply reservoir, a control reservoir, a relay valve device operative on an increase in the pressure of the fluid supplied thereto to supply fluid under pressure from the supply reservoir to the brake cylinder, valve means for supplying fluid under pressure from the control reservoir to the relay valve device, a valve device subject to and operated on a reduction in the pressure of the fluid in the brake pipe to supply fluid under pressure to the relay valve device, and means for supplying fluid under pressure from the supply pipe to the control reservoir.

12.,In a fluid pressure brake equipment, in combination, a brake cylinder, a brake pipe, a local supply reservoir, a local control reservoir, a relay valve device operative on an increase in the pressure of the fluid supplied thereto to supply fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for supplying fluid under pressure to the relay valve device, valve means for supplying fluid under pressure from the control reservoir to the relay valve device, and a valve device subject to and operated on a reduction in the pressure of the fluid in the brake pipe for supplying fluid under pressure to the relay valve device.

13. In a fluid pressure brake equipment, in combination, a brake cylinder, a brake pipe, a local supply reservoir, a local control reservoir, a relay valve device operative on an increase in the pressure of the fluid supplied thereto to supply fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for supplying fluid under pressure to the relay valve device, valve means for supplying fluid under pressure from the control reservoir to the relay valve device, and a valve device subject to and operated on a reduction in the pressure of the fluid in the brake pipe for supplying fluid under pressure from ,the supply reservoir to the relay valve device.

14. In a fluid pressure brake equipment, in combination, a brake cylinder, a brake pipe, a supply reservoir, a control reservoir, a relay valve device operative on an increase in the pressure of the fluid supplied thereto to supply fluid under pressure from the supply reservoir to the brake cylinder, manually controlled valve means for supplying fluid under pressure to the relay valve device, electroresponsive valve means for supply ing fluid under pressure from the control reservoir to the relay valve device, and a valve device subject to and operated on a reduction in the pressure of the fluid in the brake pipe for supplying fluid under pressure to the relay valve device.

15. In a fluid pressure brake equipment, in

combination, a brake cylinder, a brake pipe, a control pipe, a supply reservoir, a control reservoir, a relay valve operated on an increase in fluid pressure to supply fluid from the supply reservoir to the brake cylinder, a communication through which fluid under pressure may be supplied from the control pipe to the relay valve, a check valve operative to prevent flow of fluid from the relay valve to the control pipe through said communication, means for supplying fluid from the control reservoir to said control pipe, and changeover valve means responsive to the pressure of the fluid in the brake pipe for controlling a communication between the relay valve and the control pipe which by-passes said check valve.

16. A brake equipment as described in claim 15 and in which the changeover valve means also controls the supply of fluid from the supply reservoir to the relay valve.

17. A brake equipment as described in claim 15 and characterized by means for supplying fluid from the brake pipe to the control reservoir.

ELLIS E. HEWITT. 

